Callisto

In this chapter, we delve into an extensive examination of Callisto, the third largest moon within our Solar System and a fascinating ocean world. Our exploration begins with an in-depth review of its initial discovery by Galileo, followed by a comprehensive analysis of the observations made over the centuries preceding the era of spacecraft exploration. The observations conducted by spacecraft which provided unprecedented insights into Callisto’s surface features and geological characteristics are reviewed in detail. We also review the mechanisms that can alter a planetary surface, such as what has taken place on Callisto. Furthermore, we provide insights into the lines of evidence bolstering the hypothesis that Callisto harbors a subsurface ocean concealed beneath its icy shell, endeavoring to elucidate its nature and characteristics. Additionally, we explore the concept of habitability within the context of Callisto, contemplating the potential conditions that could support life.